Ni-Cr-Mo-V钢在深海环境的长期服役过程中会受到复杂力学环境的影响，可能会引发严重的腐蚀失效。为探究静水压力环境中Ni-Cr-Mo-V钢的应力腐蚀开裂敏感性，采用电化学测试方法、微观形貌表征手段和慢应变速率拉伸实验研究了静水压力和拉伸应力交互作用下Ni-Cr-Mo-V钢的局部腐蚀行为和应力腐蚀行为。结果表明，静水压力和拉伸应力交互作用对Ni-Cr-Mo-V钢局部腐蚀行为的双重作用会影响其应力腐蚀行为。一方面，拉伸应力与静水压力的交互作用加速了点蚀坑的扩展，并影响了腐蚀产物在基体表面的附着。另一方面，静水压力和拉伸应力促进了金属离子在Ni-Cr-Mo-V钢表面的水解，从而导致金属表面积累更多的H⁺。

With the promotion of the deep-sea strategy of China, the safety of metallic structural materials in deep sea is considered critical for development of deep-sea engineering equipment. High-strength low-alloy (HSLA) steel is widely used in pressure hulls of deep-sea submarines and oil platforms. However, HSLA steel is affected by the complex mechanical environment during its long-term service in the deep sea, leading to severe corrosion failure. Therefore, research on the effects of the hydrostatic pressure and tensile stress in deep sea on the stress corrosion behavior of HSLA steel is beneficial for the development, application, and lifetime prediction of deep-sea engineering equipment. Here, experiments were conducted using Ni-Cr-Mo-V steel, and the electrochemical measurement system and slow strain rate tensile (SSRT) test system in a simulated deep-sea environment were established in laboratory. The electric double-layer structure at the metal-solution interface was investigated using the differential capacitance curve, and the corrosion current density of the alloy was characterized with the linear polarization curve. The morphology of pits at local corrosion sites and fracture after the SSRT test were observed through SEM, and the size of the pits was analyzed using white-light interferometry. The stress corrosion cracking (SCC) sensitivity of the alloy was studied utilizing the SSRT test. The effects of the hydrostatic pressure and deformation on the concentration of H⁺ near the alloy surface were determined via the hydrolysis of metal cations. The results illustrated that the hydrostatic pressure can improve the SCC susceptibility of Ni-Cr-Mo-V steel in 3.5%NaCl solution, which can be affected by the dual effects of the interaction of the hydrostatic pressure and tensile stress on the local corrosion behavior. On the one hand, the interaction of the tensile stress and hydrostatic pressure affects the expansion and structure of pits and suppresses the adhesion of corrosion products to the alloy surface. On the other hand, the hydrostatic pressure and tensile stress affect the electric double layer at the metal-solution interface and subsequently promote the hydrolysis of metal cations, increasing the H⁺ concentration near the alloy surface. Additionally, the fracture mode of Ni-Cr-Mo-V steel in 3.5%NaCl solution is independent of the hydrostatic pressure; however, the hydrostatic pressure determines the shallow and small structure of the dimples in the fracture.